What is the main characteristic of the El Niño-Southern Oscillation (ENSO)?

The main characteristic of the El Niño-Southern Oscillation (ENSO) is changes in oceanic and atmospheric conditions. ENSO is a complex climate pattern that involves periodic fluctuations in sea surface temperatures and atmospheric pressure in the central and eastern Pacific Ocean. This phenomenon significantly alters weather patterns globally, influencing rainfall, temperature, and storm activity in various regions. For instance, during an El Niño event, the warming of ocean waters can lead to increased precipitation in some areas and drought in others, thereby impacting agricultural productivity, water supply, and ecosystems.

The term "Southern Oscillation" refers to the accompanying changes in air pressure that occur in the atmosphere. These coupled ocean-atmosphere interactions are the foundation of ENSO, making the assessment of oceanic and atmospheric conditions critical to understanding its effects and forecasting its occurrence.